Hitherto, it has been proposed to polymerize by heating an acetylene compound in the presence of silver or palladium. However, an acetylene compound which is used conventionally is generally difficult to dissolve in water and organic solvents, and thus the procedures for polymerization reaction are troublesome.
In order to produce films and fibers of a polymer, methods are generally employed in which a solution comprising an organic solvent and a reaction composition dissolved therein is cast on a support or drawn from a nozzle. If the reaction composition is difficult to dissolve in the solvent, the above methods cannot be employed or, at least, the films and fibers obtained are inferior in uniformity.
A silver mirror surface, particularly a mirror presently used, is generally produced by chemical plating in which an ammoniacal solution of silver nitride is reduced with an aldehyde as described, e.g., in U.S. Pat. No. 2,533,454. However, because this method is difficult to control, a thin silver film having a thickness of about 0.1 .mu.m and light transmission cannot be produced easily, and maintenance of a silver plating bath is difficult.
Recently, in view of the easiness of controlling the reaction, physical methods such as vapor deposition and sputtering are employed for producing a thin metallic film such as a thin silver film. However, these physical methods such as vapor deposition and sputtering are generally expensive in the manufacturing device, and thus costs of the product become disadvantageously high.
Compounds containing Group IB or VIII elements are known to be usable as a catalyst for activating a nonmetal surface in a wet chemical plating process which uses no electrode (as described in JP-A-No. 57-43977 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), and DE No. 2,934,580).
A conventional process for forming a metal coat on a non-conductive or semiconductive base without utilizing electric energy involves the steps of, in sequence, cleaning a base surface, soaking the base in a bath containing stannous chloride or another stannous salt, washing the resulting base, soaking the base in a bath containing such a metal salt as to accelerate the deposition of a desired metal (e.g., silver nitrate, gold chloride, palladium chloride, or platinum chloride), reducing the metal ion of the above-described bath with the stannous ion adsorbed on the base and/or a reducing agent contained in a metal salt bath for nonelectrode plating which is to be applied to the next step to obtain a catalytically activated surface, and treating the catalytically activated surface with a solution containing the desired metal in the presence of the reducing agent (or treating with the metal salt bath for nonelectrode plating) to deposit the desired metal, e.g., copper, nickel, and cobalt. This process and processes analogous thereto are generally called "ionizing activation".
On the other hand, German Patent Publication No. 1,197,720 describes a process of activating the surface of a polymer base upon plating thereof. According to this process, a colloidal solution of metallic palladium is prepared by introducing tin(II) chloride into a chloric acid/palladium chloride solution. This colloidal solution is supposed to be stabilized by stannic acid and tin(IV) oxychloride. Therefore, this process is generally called "colloidal activation". These colloidal particles are deposited on the base surface, and, in the subsequent step, they are activated by an acid, alkali or salt present in an appropriate concentration, whereby they are converted to palladium particles through the removal of the protective colloid to result in formation of a catalytically activated surface on the base. These palladium particles act as catalyst nuclei for nonelectrode copper or nickel plating to be performed in the next step.
In this process, it is necessary to perform a washing step between every two subsequent steps.
However, these conventional activation processes have the following defects.
First, several processing steps (including activation, sensitization, washing and the like) are required for completion of a catalytically activated surface which is applicable to nonelectrode plating, which renders the process complex and expensive.
Second, the range of application of these processes is not wide. In general, application of these processes is limited, if anything, to bases of which surfaces have received a pretreatment using a chemical or mechanical means. Such a pretreatment of a base as described above, which needs to be carried out prior to chemical plating and subsequent electroplating, is also described in R. Weiner, Kunststoff Galvanisierung (Eugen G. Lewze Verlag, Saulgauwelt, 1973).
This pretreatment generally includes etching the surface of a base (made from a polymer in many cases) with, e.g., chromium sulfate, detoxicating with a dilute solution of sodium hydrogen sulfite as a washing step is interposed several times, and further washing the resulting surface. After the pretreatment as described above, an appropriate activation treatment like the foregoing ionizing or colloidal activation is carried out.
The etching step changes the surface of a polymer base to result in formation of bites and voids. This effect can be obtained only when the base is made from a particular polymer. Examples of such a particular polymer include ABS polymer, binary phasic multicomponent graft polymers or copolymers like shock resistant polystyrenes, and binary phasic homopolymers like partly crystalline polypropylenes. In addition, the use of chromium sulfate or other oxidizing agents is attended by deterioration of physical properties of a polymeric substance constituting a base, such as a strength to notch shock and an electric surface resistance.
For enhancing adhesiveness of catalyst nuclei to a base, there are methods disclosed in JP-A-Nos. 57-43977, 58-104170 and 61-15984, which involve using metal complexes of the kind which contain both a group capable of entering into combination with a metal and a group having an affinity to a base in a molecule. However, such methods fail to provide satisfactory adhesiveness, because their adhesion power arises basically from adsorption of the metal complexes to the base.
Third, when metallic particles like metallic palladium are densely arranged (even though on a part of the surface), an undesirable connection occurs in forming a printed circuit pattern by nonelectrode plating. Because of the apprehension of connection, the full additive process, though a simple process for producing a base plate for a printed circuit, is not suitable for use. Under these circumstances, production processes which require complex steps, such as the subtractive process and the semiadditive process, are generally used.